The Big Programming Thread - Page 492

On June 20 2014 03:05 Ethenielle wrote:
After reading about the observer pattern, I think that's pretty much what I'm doing now.

Anyway, for the class that I expose to the user it looks something like this:

class PointLight
{ 
int radius;
float pos[3];
[..] etc

vector<Callback> callbacks;

public:
void AddCallback(...);
void X(float x) 
{
 // set x
 // trigger callbacks
}

};

Then whenever the user adds a light to the scene, the engine would create an internal PointLight class which stores additional information that only the engine needs to know about, and it would also register a callback with the exposed class. Something like this:

struct PointLight_Internal
{
 PointLight* exposed;
 DirectX::XMFLOAT4X4 viewTransform;
 ShadowMapOmni smap;
 [...]

 void OnPropertyChanged(...); // This would recalculate dependent variables such as viewTransform when position changes
};

void Engine::AddLight(PointLight& pl)
{
PointLight_Internal pli;
pli.exposed = &pl;
pl.AddCallback(pli.OnPropertyChanged)

lights.push_back(pli);
}

And then the rendering would obviously only operate on the internal class. So then I get the benefit of hiding these engine-only relevant variables from the user, but in their stead there is this "mysterious" array of callbacks. Ideally, the class I expose to the user would just be a POD class. Maybe that's not possible without constantly polling/updating dependent variables, though. I hope that was maybe a bit clearer explanation of my problem...?

On June 20 2014 06:56 Nesserev wrote:
It might be a bit rude even though I mean no offense, and it's only based on a hunch, but do you even understand how a graphics engine is supposed to work?

EDIT: Now that I think about it, asking this question doesn't help in any way... from what you've described about your engine so far, it just seems that the design of your engine is rather flawed.

On June 21 2014 00:24 Ethenielle wrote:
Initially that's what I did. But the engine needs access to those private variables for rendering, so then I had to friend the engine. I didn't like that, so that's why I ended up splitting the class in two, and that leads to the whole callback messy situation, which isn't good either.

On June 19 2014 01:41 Ethenielle wrote:
That's what I'm doing, but the internal classes have to know whenever the user changes something in the public class, thus the callbacks. Which I don't like.. the user shouldn't know about that, either.

On June 21 2014 10:43 darkness wrote:
Has anyone got any experience with Java 8? Is there anything that is 'must learn'? I've seen lambda expressions, but they seem weird to me; not verbose enough.

On June 21 2014 03:06 urboss wrote:

Why not use an abstract class and derive the public class from it?

On June 21 2014 08:29 Nesserev wrote:

[...]

On June 21 2014 18:36 Ethenielle wrote:
Maybe the "best" solution really is to put all relevant variables in their respective class and friend the engine...? Even though friend is anathema.

On June 21 2014 10:46 phar wrote:
^

As a meta point in software development, it is good to develop a thick skin to questions that seem overly blunt. A lot of people aren't trying to be mean, they just might not present things in super nice ways. People are also often very willing to teach and explain things, because helping other people understand how things work is the only way any shit gets done in software. Modern software is way too big and complex for any one person to do alone.

Sometimes a question "do you know how X works?" is literally just that - a query to see how much knowledge/experience you have on a specific topic, so people can help you learn more.

(Of course sometimes people can take it too far)


No direct experience yet, because my company has yet to bless java 8 for production environments, and I haven't had any time to dick around with experimental stuff.

That said, can't wait for lambda expressions. Gonna remove a lot of bullshit anonymous classes that you have to hack in to do stuff that shouldn't be super hard to write. Also interested to see what tooling I'm gonna have access to around type annotations, though my guess is it's gonna be years out for me


I was just joking with a co-worker today - "What if the powers that be directing java are secretly haskell fanatics, and by java 12 we suddenly get full blown functional goodness?" http://res.cloudinary.com/readnuts-com/image/upload/c_fit,h_350,w_350/jayr9ifjyl9ztmjflk32.jpg

:\

On June 24 2014 10:56 billy5000 wrote:
Got a question about eclipse. We have a workspace that consists of many projects, and there's a bit of a delay. Ideally, I would like to load a single project on eclipse rather than loading all of them. So instead of the root being the workspace, it would be the project. Is there a way to do this?

On June 24 2014 20:32 berated- wrote:


Where is the "bit of delay" you are trying to get rid of?

Sorry if you have already tried this, or if this isn't where your delay is, but, have you tried closing the projects you aren't using? I've had 75+ projects in a workspace and if a lot of the projects were open it would bog it down, but if you just close the projects you aren't using then everything was fast.